I just got a CV.OCD which is a very affordable MIDI-CV converter:
While it doesn’t specifically support MPE, it does handle monophonic pitch bend up to 24 semitones and of course converts CC74, channel aftertouch, etc. to control voltages.
I just tried it out with my Linnstrument and modular synth and it works great. I’m using last note priority to play monophonically, but with the expressive features of the MPE controller:
I assume it kind of feels like using the Haken Continuumini.